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36 records – page 1 of 4.

Adhesive Bonding of Structural Hardwood Elements

https://research.thinkwood.com/en/permalink/catalogue75
Year of Publication
2015
Topic
Mechanical Properties
Serviceability
Moisture
Material
Glulam (Glue-Laminated Timber)
CLT (Cross-Laminated Timber)
Author
Hassani, Mohammad
Organization
ETH Zurich
Year of Publication
2015
Country of Publication
Switzerland
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Serviceability
Moisture
Keywords
Abaqus
Adhesives
Beech
Bonding
Delamination
Finite Element Model
Fracture
Long-term
Model
Hardwood
Language
English
Research Status
Complete
Summary
The current research investigated the delamination process of adhesively bonded hardwood (European beech) elements subject to changing climatic conditions. For the study of the long-term fracture mechanical behavior of gluedlaminated components under varying moisture content, the role of moisture development, time- and moisture-dependent responses are absolutely crucial. For this purpose, a 3D orthotropic hygro-elastic, plastic, visco-elastic, mechano-sorptive wood constitutive model with moisture-dependent material constants was presented in this work. Such a comprehensive material model is capable to capture the true historydependent stress states and deformations which are essential to achieve reliable design of timber structures. Besides the solid wood substrates, the adhesive material also influences the interface performance considerably. Hence, to gain further insight into the stresses and deformations generated in the bond-line, a general hygro-elastic, plastic, visco-elastic creep material model for adhesive was introduced as well. The associated numerical algorithms developed on the basis of additive decomposition of the total strain were formulated and implemented within the Abaqus Finite Element (FE) package. Functionality and performance of the proposed approach were evaluated by performing multiple verification simulations of wood components, under different combinations of mechanical loading and moisture variation. Moreover, the generality and efficiency of the presented approach was further demonstrated by conducting an application example of a hybrid wood element.
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Advanced Modelling of Cross Laminated Timber (CLT) Panels in Bending

https://research.thinkwood.com/en/permalink/catalogue1796
Year of Publication
2015
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Franzoni, Lorenzo
Lebée, Arthur
Lyon, Florent
Forêt, Gilles
Publisher
HAL archives-ouvertes.fr
Year of Publication
2015
Country of Publication
Germany
Format
Presentation
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Mechanical Properties
Keywords
Bending
Model
Panels
Shear
Stiffness
Failure Behavior
Shear Force
Reference Test
Language
English
Conference
Euromech Colloquim 556 Theoretical Numerical and Experimental Analyses of Wood Mechanics
Research Status
Complete
Notes
May 2015, Dresde, Germany
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Free
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Air-Borne Sound Transmission through Triple-Leaf Walls

https://research.thinkwood.com/en/permalink/catalogue2235
Year of Publication
2015
Topic
Acoustics and Vibration
Material
Light Frame (Lumber+Panels)
Application
Walls
Author
Eslami, Armin
Organization
Carleton University
Year of Publication
2015
Country of Publication
Canada
Format
Thesis
Material
Light Frame (Lumber+Panels)
Application
Walls
Topic
Acoustics and Vibration
Keywords
Mid-Rise
Airborne Sound
Model
Sound Transmission
Sound Insulation
Language
English
Research Status
Complete
Online Access
Free
Resource Link
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An Algorithm for Numerical Modelling of Cross-Laminated Timber Structures

https://research.thinkwood.com/en/permalink/catalogue2362
Year of Publication
2015
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
D'Aronco, Gabriele
Publisher
Università di Padova
Year of Publication
2015
Country of Publication
Italy
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Keywords
Connections
Panels
Model
Language
English
Research Status
Complete
Summary
Cross-laminated timber, also known as X-Lam or CLT, is well established in Europe as a construction material. Recently, implementation of X-Lam products and systems has begun in countries such as Canada, United States, Australia and New Zealand. So far, no relevant design codes for X-Lam construction were published in Europe, therefore an extensive research on the field of cross-laminated timber is being performed by research groups in Europe and overseas. Experimental test results are required for development of design methods and for verification of design models accuracy. This thesis is part of a large research project on the development of a software for the modelling of CLT structures, including analysis, calculation, design and verification of connections and panels. It was born as collaboration between Padua University and Barcelona"s CIMNE (International Centre for Numerical Methods in Engineering). The research project started with the thesis “Una procedura numerica per il progetto di edifici in Xlam” by Massimiliano Zecchetto, which develops a software, using MATLAB interface, only for 2D linear elastic analysis. Follows the phase started in March 2015, consisting in extending the 2D software to a 3D one, with the severity caused by modelling in three dimensions. This phase is developed as a common project and described in this thesis and in “Pre-process for numerical analysis of Cross Laminated Timber Structures” by Alessandra Ferrandino. The final aim of the software is to enable the modelling of an X-Lam structure in the most efficient and reliable way, taking into account its peculiarities. Modelling of CLT buildings lies into properly model the connections between panels. Through the connections modelling, the final aim is to enable the check of preliminarily designed connections or to find them iteratively, starting from hypothetical or random connections. This common project develops the pre-process and analysis phases of the 3D software that allows the automatic modelling of connections between X-Lam panels. To achieve the goal, a new problem type for GiD interface and a new application for KRATOS framework have been performed. The problem type enables the user to model a CLT structure, starting from the creation of the geometry and the assignation of numeric entities (beam, shell, etc.) to geometric ones, having defined the material, and assigning loads and boundary conditions. The user does not need to create manually the connections, as conversely needs for all commercial FEM software currently available; he just set the connection properties to the different sides of the panels. The creation of the connections is made automatically, keeping into account different typologies of connections and assembling of Cross-Lam panels. The problem type is special for XLam structures, meaning that all features are intentionally studied for this kind of structures and the software architecture is planned for future developments of the postprocess phase. It can be concluded that sound bases for the pre-process and analysis phases of the software have been laid. However, future research is required to develop the postprocess and verification phases of the research project.
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Analysis of the Timber-Concrete Composite Systems with Ductile Connection

https://research.thinkwood.com/en/permalink/catalogue113
Year of Publication
2013
Topic
Mechanical Properties
Material
Timber-Concrete Composite
Author
Zhang, Chao
Organization
University of Toronto
Year of Publication
2013
Country of Publication
Canada
Format
Thesis
Material
Timber-Concrete Composite
Topic
Mechanical Properties
Keywords
Bending
Ductility
Model
Load Deflection
Tension
Shear Connection
Language
English
Research Status
Complete
Summary
In timber-concrete composite systems, timber and concrete are inherently brittle materials that behave linearly elastic in both tension and bending. However, the shear connection between the members can exhibit significant ductility. It is therefore possible to develop timber-concrete composite systems with ductile connection that behave in a ductile fashion. This study illustrates the use of an elastic-perfectly plastic analytical approach to this problem. In addition, the study proposes an incremental method for predicting the nonlinear load-deflection response of the composite system. The accuracy of the analytical model is confirmed with a computer model, and numerical solutions of the analytical model are compared to experimental results from the bending tests conducted by previous researchers. Reasonable agreement is found from the comparisons, which validates the capacity of the analytical model in predicting the structural behaviour of the timber-concrete composite systems in both elastic and post-elastic stages.
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An Analytical Model for Design of Reinforcement around Holes in Laminated Veneer Lumber (LVL) Beams

https://research.thinkwood.com/en/permalink/catalogue135
Year of Publication
2013
Topic
Design and Systems
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Author
Ardalany, Manoochehr
Fragiacomo, Massimo
Moss, Peter
Deam, Bruce
Publisher
Springer Netherlands
Year of Publication
2013
Country of Publication
Netherlands
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Topic
Design and Systems
Mechanical Properties
Keywords
Failure
Glued-In Rods
Model
Reinforcement
Screws
Tensile
Language
English
Research Status
Complete
Series
Materials and Structures
ISSN
1871-6873
Summary
Openings are usually required to allow services like plumbing, sewage pipes and electrical wiring to run through beams. This prevents an extra depth of the floor/ceiling, while preserving architectural considerations. The introduction of large opening causes additional tension perpendicular to grain in timber beams. The low tensile strength perpendicular to grain of wood allows crack formation. Crack propagation around the hole considerably decreases the load-carrying capacity of the beam. However, in most cases, crack formation and propagation around the hole can be prevented by the use of an appropriate reinforcement. Screw, glued-in rods, and plywood are alternative options for the reinforcement. Design of the reinforcement requires that the working mechanism of the reinforcement is fully understood and properly addressed. In addition, reinforcement should be designed for actions produced in the section of the beam weakened by the hole. The current paper uses a simple truss model around the opening to calculate the tensile force in the reinforcement. Two simple formulations for design of the reinforcement are derived and compared with numerical and experimental results, showing an overall good correspondence. The proposed truss model can be considered for incorporation in future codes of practice.
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An Approach to CLT Diaphragm Modeling for Seismic Design with Application to a U.S. High Rise Project

https://research.thinkwood.com/en/permalink/catalogue1671
Year of Publication
2016
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Floors
Wood Building Systems
Author
Breneman, Scott
McDonnell, Eric
Zimmerman, Reid
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Floors
Wood Building Systems
Topic
Seismic
Design and Systems
Keywords
US
Diaphragm
Model
High-Rise
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3844-3852
Summary
A candidate CLT diaphragm analysis model approach is presented and evaluated as an engineering design tool motivated by the needs of seismic design in the United States. The modeling approach consists of explicitly modeling CLT panels as discrete orthotropic shell elements with connections between panels and connections from panels to structural framing modelled as two-point springs. The modeling approach has been compared to a developed CLT diaphragm design example based on U.S. standards showing the ability to obtain matching deflection results. The sensitivity of the deflection calculations to considering CLT panel-to-panel connection gap closure is investigated using a simple diaphragm example. The proposed modeling approach is also applied to the candidate floor diaphragm design for the Framework project, one of the two U.S. Tall Wood Building Prize Competition winners, currently under design. Observations from this effort are that the proposed method, while a more refined model than typically used during building design, shows promise to meet the needs of innovative CLT seismic designs where appropriate simpler diaphragm models are not available.
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An Approach to CLT Diaphragm Modeling for Seismic Design with Application to a U.S. High-Rise Project

https://research.thinkwood.com/en/permalink/catalogue1710
Year of Publication
2017
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Floors
Author
Breneman, Scott
McDonnell, Eric
Zimmerman, Reid
Organization
WoodWorks
Year of Publication
2017
Country of Publication
United States
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Floors
Topic
Design and Systems
Seismic
Keywords
US
Model
Diaphragm
High-Rise
Language
English
Research Status
Complete
Summary
A candidate cross-laminated timber (CLT) diaphragm analysis model approach is presented and evaluated as an engineering design tool motivated by the needs of seismic design in the United States. the modeling approach consists of explicitly modeling CLT panels as discrete orthotropic shell elements with connections between panels and connections from panels to structural framing modeled as two-point springs. The modeling approach has been compared to a developed CLT diapragm design example based on the US standards showing the ability to obtain matching deflection results. The sensitivity of the deflection calculations considering CLT panel-to-panel connection gap closure is investigated using a simple diaphragm example. the proposed modeling approach is also applied to the candidate floor diaphragm design for the Framework project, a winner of the US Tall Wood Building Prize Competition, currently under design. Observations from this effort are that the proposed method, while a more refined model than typically used during building design, shows promise to meet the needs of innovative CLT seismic designs where appropriate simpler diapragm models are not available.
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Assessing The Flammability of Mass Timber Components: A Review

https://research.thinkwood.com/en/permalink/catalogue87
Year of Publication
2014
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
PSL (Parallel Strand Lumber)
Application
Wood Building Systems
Author
Mehaffey, Jim
Dagenais, Christian
Organization
FPInnovations
Year of Publication
2014
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
PSL (Parallel Strand Lumber)
Application
Wood Building Systems
Topic
Fire
Keywords
National Building Code of Canada
Flame Spread
Model
Cone Calorimeter Testing
Buildings
Language
English
Research Status
Complete
Summary
This report begins with a discussion of the mechanisms of flame spread over combustible materials while describing the NBCC prescriptive solutions that establish the acceptable fire performance of interior finish materials. It is noted that while flame spread ratings do give an indication of the fire performance of products in building fires, the data generated are not useful as input to fire models that predict fire growth in buildings. The cone calorimeter test is then described in some detail. Basic data generated in the cone calorimeter on the time to ignition and heat release rates are shown to be fundamental properties of wood products which can be useful as input to fire models for predicting fire growth in buildings. The report concludes with the recommendation that it would be useful to run an extensive set of cone calorimeter tests on SCL, glue-laminated timber and CLT products. The fundamental data could be most useful for validating models for predicting flame spread ratings of massive timber products and useful as input to comprehensive computer fire models that predict the course of fire in buildings. It is also argued that the cone calorimeter would be a useful tool in assessing fire performance during product development and for quality control purposes.
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Bending Tests on Glued Laminated Timber Beams with Well-Known Material Properties

https://research.thinkwood.com/en/permalink/catalogue186
Year of Publication
2013
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Fink, Gerhard
Kohler, Jochen
Frangi, Andrea
Organization
ETH Zurich
Year of Publication
2013
Country of Publication
Switzerland
Format
Report
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Bending Strength
Failure
Load Bearing Capacity
Four Point Bending Test
Density
Model
Bending Stiffness
Language
English
Research Status
Complete
Summary
At the Institute of Structural Engineering at the ETH Zurich numerous of investigations are conducted to analyse the load bearing capacity of glued laminated timber beams. The investigations are part of the research project ’Influence of varying material properties on the load bearing capacity of glued laminated timber (glulam)’. The investigations are taking place on 24 glulam beams with well-known material properties. The glulam beams are fabricated out of 400 timber boards. From those boards the material properties are investigated non-destructively within a former research project. During the glulam fabrication it is particularly focused to keep the information of the timber boards; i.e. after the glulam fabrication the position of each particular timber board within the glulam beam and thus the position of each particular knot is still known. The glulam beams are investigated during a 4-point bending test. On the glulam members the load bearing capacity, the bending stiffness and the density is measured. Furthermore local strains within the glulam beams are investigated using an optical coordinate-measurement device. Following the test the failure is investigated in detail. Hereby the type of failure (knot cluster, finger joint, clear wood) and the amount of failure (number of damaged lamellas) is documented. Afterwards the failed glulam beams are loaded again to analyse the remaining bending strength and the corresponding remaining bending stiffness. The major aim of the experimental analysis is the investigation of the load bearing capacity of glulam beams with well-known local material properties. The gained results can be used for an investigation of the influence of local weak zones, such as knot clusters or finger joints, on the load bearing capacity of glulam. In addition a data basis is produced to develop a new model (or to evaluate existing models) for the estimation of the load bearing capacity of glulam.
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36 records – page 1 of 4.